Protecting treatment for wood



United States Patent 3,305,298 PROTECTING TREATMENT FOR WOOD Alfred Dale Chapman, Atherton, and Robert E. Stutz, Los Altos Hills, Califi, assignors to Chapman Chemical Company, Memphis, Tenn., a corporation of Tennessee No Drawing. Filed Nov. 30, 1964, Ser. No. 414,874 8 Claims. (Cl. 21-7) This invention relates to a novel and highly eifective fungicidal, bactericidal system for use in the chemicalmechanical control of so-called sap stain, mold discolorations, and decay infections in lumber and veneers.

It has long been the commercial practice at lumber and veneer mills to dissolve by hand in water a dry or liquid form of a fungicidal compound, and thus prepare a preservative solution with which the freshly cut wood was treated by being dipped or sprayed to protect it from fungus attack during seasoning. This method is not only laborious, time consuming, and costly, but often results in irritation to the workmen and poor control of solution strengths, with subsequent inferior microbial control. Moreover, until now, none of the chemical formulations used, have been fully effective against the wide range of microorganisms involved. Some fungicidal-bactericidal systems controlled the Ascomycetes and Fungi imperfecti well, but were weak against certain molds, and other systems gave just the reverse pattern of results. Certain of the chemical solutions used to effect microbial control are unstable when recycled over the acidic wood and this results in formation of precipitates and sludges. The net effect of this behavior is to cause loss of strength and poor performance in the control of the microbial organisms. There has been a long standing need in the industry to have an effective liquid concentrate that could be handled at the mill site without irritation to the workmen, that could readily be diluted in efiicient mechanical metering devices to provide a ready-to-use solution of known concentration that did not have the attendant problems of sludging and precipitation that are inherent in other microbial control systems.

One of the widely used sapstain systems (Commercial A) has as its active materials the sodium salt of pentachlorophenol along with a borate buifer system that is capable of controlling most fungi except the Ascocyte mold. Some of the main drawbacks to this system is that in powder form its dusts readily, causes respiratory and dermal irritation to workmen, and requires them to use special techniques to prepare the ready-to-use solutions at the mill sites.

Another widely used sapstain control system (Commercial B) has as its active ingredients the sodium salt of pentachlorophenol, ethyl mercury phosphate and a borate buffer system. This particular system controls the Ascocyte mold, but does not have the same elfectiveness against white and green mold as does Commercial A. In addition, it is a powdery material that requires dissolution at the plant site with the attendant mixing and handling problems associated with these operations. Further, it has an objectionable odor.

It has been a long sought for goal by the sapstain control industry, as well as the lumber industry, to find an effective liquid sapstain control system that would be effective against a broad spectrum of wood attacking microorganisms and could be used with automatic metering devices amenable to saw mill practices to produce a ready-to-use solution of uniform concentration with a minimal amount of labor and eifort on the part of the operating mill personnel. Until the present instant invention of the novel compositions of this invention these. goals have been the long cherished wishes and dreams of the lumber industry.

One of the principal objects of this invention is to provide novel and improved liquid forms of a fungicidalbactericidal stable concentrate for the preservative treatment of wood that can be used in automatic mechanical mixing and metering devices to produce a ready-to-use solution of uniform strength that is resistant to the sludg ing and to the precipitation phenomena.

A still further object of this invention is to provide a stable liquid concentrate and buffered solution, which will not precipitate or sludge during normal storage and use, in conventional or automatic dispersion equipment.

It is a further object of this invention to provide a simple, accurate, labor-efiicient, safe, and automatic method of providing a ready-to-use solution for the wood industry and to eliminate the time consuming practice of preparing ready-to-use solutions from concentrates and dry powders that are instable and are irritating to the workmen.

A still further object of this invention is to provide an economical product which is uniformly effective against all forms of the wood degrading fungi involved.

Other objects and advantages of this invention will be readily apparent from the following disclosure and detailed description.

These and other objects and advantages of this invention are attained by use of a new process, which is to react certain halogenated phenols with certain phenylated or acylated mercury compounds in the presence of a mild buifermg agent. This process greatly improves the storage life, the working qualities, and the sludging resistance of the product. The resulting liquid product of this invention allows the careful and automatically controllable metering of the product into a water supply to provide ready-to-use solutions of uniform strength with a minirnum amount of handling and without irritation to working personnel.

Until now, all dry and liquid products made for the purpose of controlling wood attacking fungi and bacteria have one or more shortcomings in providing complete control. The products are, irritating to the workmen, ineffective against some specific microbial organisms, such as to require undue handling by mill workers to produce unlform working solutions, and not subject to easy reclaim and recycling for efiicient economical use. For example a commercially available dry combination of chloro phenates and borates (sold by the assignee of the instant application) was a great improvement over the straight chlorophenates, since it reduced irritation, prevented sludging, and extended the range of fungicidal activity; but it was bulky, still somewhat irritating, and not effective against certain molds such as Ascocyte, a fungus of growing importance.

Likewise, another commercial composition which uses chlorophenates and organic (acyl) mercury derivatives in a dry powder form, proved to be irritating, odorous, hazardous to the workmen, and not sufliciently effective against all the degrading fungi involved. In fact, under prolonged seasoning conditions on yellow pine, it would often stimulate the growth of green molds in much the same manner as when organic mercury compounds are used alone under prolonged seasoning conditions.

All of the liquid products tried by industry to date have not been stable, either in the concentrate form or when diluted for use. If the buifers used are too alkaline, the organic mercury components are degraded and lost; if not buffered enough, the halogenated phenols drop out and are largely lost; in any case, the liquid products used in the past have not been successful. Our present composition, however, is unique. It combines known compounds for the first time in a way which gives high stability, no odor or corrosiveness in the concentrate or diluted forms, permits use in a metering device, and gives consistently excellent control of all important degrading fungi in an economical way.

It has further been discovered that ordinary buffering agents such as trisodium phosphate, soda ash, and sodium bicarbonate do not work well in this system, and that the type of borate buffer system used in the formulation of the invention is the only practical method to provide uniform and consistent control of a broad spectrum of microorganisms.

The production of the stable liquid concentrate, in view of the prior experiences of the industry and the art, is unexpected and novel especially when coupled with the fact that this stability is transmitted over to the diluted readyto-use solutions. The exact nature of the chemical and mechanistic forces that have permitted this unexpected result to occur are not clearly understood and are not subject to conclusive delineation. One possible explanation for this beneficial and unexpected result lies in the possibility that there are formed stable ionic complexes that can accommodate the incorporation of soluble aryl and acyl mercury compounds along with hydroxylated compounds in conjunction with the borate ion. It is understood, of course, that the foregoing theory is by way of explanation and not limitation. This unexpected result surprisingly is limited to the borate ion as the buffering system and is not subject to prediction.

The stable liquid concentrates of the instant invention comprise mixtures prepared from Water, methanol, ethylene glycol, propylene glycol ethers, halogenated phenols, soluble borates, organic mercury salts and alkali metal hydroxides.

The halogenated phenols that are useful in this invention are pentachlorophenol, 2,3,4,6-tetrachlorophenol, 2,3,5,6-tetrach1orophenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, 2,3,6-trichloro-4-fiuorophenol and mixtures thereof. A preferred embodiment of the invention is the use of a commercial mixture of chlorinated phenols that consists essentially of 2,3,4,6-tetrachloropher1ol and pentachlorophenol. A still more preferred embodiment of the invention is the use of a mixture of halogenated phenols that are defined as a stable, free-flowing solid, melt-derived complex crystalline composition containing between 70 and 82.5% by weight of 2,3,4,6-tetrachlorophenol and correspondingly between 30 and 17.5% by weight of pentachlorophenol. A still further preferred embodiment of the invention is the use of a mixture of chlorinated phenols that are defined as a stable, free-flowing solid, melt-derived complex crystalline composition containing between about 80% by weight of 2,3,4,6-tetrachlorophenol and about by weight of pentachlorophenol.

The borate ion used to effect buffering in the novel compositions of the instant invention are soluble borates, borax, borax decahydrate, sodium metaborate and other boron salts capable of ready conversion to sodium metaborate in solution.

The aryl and acyl mercury salts that can be used in the liquid sapstain systems are phenyl mercuric lactate, phenyl mercuric acetate, phenyl mercuric propionate, phenyl mercuric borate, phenyl mercuric urea, phenyl mercuric hydroxide, phenyl mercuric chloride, 3-chlorophenyl mercuric acetate, 2-chlorophenyl mercuric acetate, 4- chlorophenyl mercuric acetate, 3-nitrophenyl mercuric lactate, ethyl mercuric acetate, methyl mercuric acetate as well as other aryl and acyl mercury salts that are readily apparent to those skilled in the art. A preferred embodiment of the invention is phenyl mercuric lactate.

The liquid novel sapstain control concentrates can be prepared in the following manner in a suitable reactor: the water, the soluble borate, and diluted alkali metal hydroxide solution are mixed and agitated to effect complete solution of these ingredients. There is usually a temperature rise as a result of solution and reaction of the alkali metal hydroxide with the soluble bo-rate compound. While the mixture is under agitation there is now added methanol, ethylene glycol, propylene glycol ethers,

the halogenated phenols and the organic mercury salts. The reaction mixture is heated to about 150 F. to effect complete solution over a period of from fifteen minutes to three hours dependent upon batch size and equipment available for heating. The sapstain control concentrate can be used directly or may be filtered to remove minor amounts of insolub-les that have been introduced along with the reactants as inerts.

A typical preparation of a novel sapstain control concentrate using some of the preferred raw materials is as follows:

A mixture of 3,809.7 parts by weight of water, 830.7 parts by weight of borax and 1,209.6 parts by weight of 50% caustic soda was prepared in the reactor and while under efficient agitation there was added thereto 887.4 parts by weight of methanol, 145.8 parts by weight of ethylene glycol, 1458 parts by weight of propylene glycol methyl ether, 2,012.4 parts by weight of a mixture of tetrachlorophenol and 20% pentachlorophenol, and 36.27 parts by weight of phenyl mercuric lactate. The reaction mixture was heated to 150 F., held at this temperature for one hour under agitation and was filtered to yield 9,077.7 parts by Weight of the liquid sapstain concentrate.

The order of addition of the reactants is not critical and is subject to efiicient manufacturing processing contingent upon the equipment being used. One of the points of criticality in the invention is the use of an excess of alkali metal hydroxide, as for example sodium hydroxide. This excess is equal to about one mole of alkali metal hydroxide per mole of B 0 present once the halogenated phenols have been neutralized and the soluble B 0 compounds have reacted with the alkali hydroxide. Larger excesses of alkali metal hydroxide cause degradation while insufficient alkali metal hydroxide does not produce stable liquid concentrates that can be metered and diluted in mechanical equipment to produce the ready-to-use solutions for spraying and dipping lumber. It is, of course, obvious that any of the alkali metals, i.e., Li, Na, K, Rb or Ce, could be used to prepare the hydroxide, but it has been noted that sodium and potassium hydroxide are preferred. The alkali hydroxide is normally diluted prior to its addition to the other ingredients used in the formulation of the instant invention. The range extending from a practical minimum of 50% (in the case of sodium hydroxide) to a practical maximum of about (in the case of potassium hydroxide), but variations there-of are possible in View of the particular alkali metal used and the desired results, such variations are, of course, within the skill of those in the art.

The variation in the active ingredients that may occur for 1 US. gallon of concentrate and still produce an effective stable system is as follows:

About 1.50 to about 7.00 lbs. of halogenated phenols About 0.01 to about 0.40 lbs. of organic mercury salts About 0.18 to about 0.80 lbs. of soluble B 0 One embodiment of our invention, designated as Permatox-IOO, described earlier, is a liquid concentrate, stable to recycling and dilution in mechanical metering and diluting equipment when one volume of such material is diluted with volumes of water to form a ready-touse solution. The following specific examples of the effectiveness of the ready-to-use solution at a 1:100 dilutron as applied to lumber are shown in comparison with typical commercial sapstain control systems, Commercial A and Commercial B. All of the materials are compared on the single strength basis, which is the rate of application usually applied under the average seasoning conditions for lumber.

EXAMPLE 1 Permatox-100 prepared as described earlier, was diluted with water at a rate of one volume of Permatox- 100 to 100 volumes of water with an automatic measuring and metering device. Test pieces of Southern Yellow Pine sapwood and heartwood lumber were given a 20 second dip in the diluted solution and were stacked with untreated control lumber under warm humid conditions of summer, conducive to rapid development of microbial growth and attack.

Besides the Permatox-lOO and the untreated control there was exposed lumber treated with two commercial sapstain control chemicals also at single strength application.

At the end of three months exposure under severe conditions the lumber was examined and the following results were observed and tabulated on the basis of percentage of surface stain.

Treatment: Percent stain Permatox-lOO 12.1 Commercial A 24.7 Commercial B 32.5 Untreated control 95.0

EXAMPLE 2 The treatment of Southern Yellow Pine lumber as per Example 1 was repeated in the same manner during the early autumn season wherein the weather conditions for microbial attack are not as severe as summer. The following results were observed:

Treatment: Percent stain Permatox-100 1.5 Commercial A 20.6 Commercial B 4.3 Untreated control 85.5

EXAMPLE 3 The treatment of lumber, in this case Western Hemlock, was carried out by spraying to run-off with the ready-to-use sapstain control chemicals a in Example 1 and exposed for four months under severe late summer 1 Impossible to read because of overgrowth of other organisms.

EXAMPLE 4 The treatment of lumber, in this case Ponderosa Pine, was repeated as in Example 1 and exposed under very severe conditions for six weeks with the following results:

Percent Stain and Mold Treatment Ceratostomella White Mold and Fungi and Ascocyte imperfecti Green Mold Permatox100 8. 0 Trace Commercial A.. 11. 5 0 56 Commercial B 12. 6 79 1. 0 Untreated Contr 85 1 Impossible to read because of overgrowth of other organisms.

EXAMPLE 5 The treatment of Southern Yellow Pine lumber was repeated as per Example v1 and was exposed for three months during the late fall and early winter months under severe conditions with the following results:

6 Treatment: Percent stain Permatox-IOO 2.0 Commercial A 20.1 CommercialB 2.0 Untreated controls 85.0

EXAMPLE 6 The purpose of this experiment was to compare the effectiveness of Permatoxtreated lumber (Southern Yellow Pine) versus the Permato-x-l00 formulation minus the organic mercury salt and the two commercial products A and B after six weeks exposure under severe conditions in the late spring and early summer. The results were as follows:

Treatment Percent stain Permatox-100 0.3 Permatox100 with no Hg 5.3 Commercial A 5.8 Commercial B 1.8 Untreated controls 78.3

EXAMPLE 7 Preparation of Permatox-IOO c0ncentrate.-There was charged into an appropriate reactor 195 grams of water, 6 0 grams of 50% sodium hydroxide, 42.5 grams of borax decahydrate, 7.5 grams of ethylene glycol, 7.5 grams of propylene glycol monomethyl ether, 103.1 grams of a stable, free-flowing solid, melt-derived complex-crystalline composition containing between 70 and 82.5% by weight of 2,3,4,6-tetraclrlorophenol and correspondingly between 30 and 17.5% by Weight of pentachlorophenol, and 1.85 grams of phenyl mercuric lactate. The reaction mixture was agitated and heated to a temperature of about F. until a clear solution was obtained. The product has the following composition as determined from the ingredients added:

EXAMPLE 8 The use of potassium hydroxide in place of 50% caustic soda has been found to the highly effective in the control of sapstain, mold and decay. Such formulation is comprised of 55.1 parts by weight of water charged into a suitable reactor together with 9.15 parts by weight of 88.92% KOH and 8.57 parts by weight of sodium tetraborate decahydrate with adequate agitation which dissolves giving a clear solution with an increase in temperature to about 150 F. with continued agitation there are added 3.02 parts by weight of ethylene glycol, 3.02 parts by weight dipropylene glycol methyl ether, 20.77 parts by weight of a crystalline melt derived mixture comprised of approximately 80% tetrachlorophenol and 20% pentachlorophenol and 0.37 parts by weight of phenyl mercuric lactate, agitated and heated for sufficient time to give a clear solution on filtration which is free from crystallization and sludging on storage and use.

The percentage composition based upon ingredients used is:

Further embodiments of the invention may be exemplified by the following demonstrations:

Demonstration A.A solution of 31.4 grams of 2,4,5- trichlorophenol in 8 milliliters of methanol is prepared, and .to this solution is added 0.5 gram of nonyl phenol ethoxylated with 9 to 10 moles of ethylene oxide. Next, a charge of 6.5 grams of sodium hydroxide is dissolved in a total of 10 milliliters of water, and this sodium hydroxide solution is added slowly to the trichlorophenol solution. To the resulting combination there is added a charge of 2 grams of powdered methoxyet-hyl mercury acetate and 0.2 gram of sodium hydroxide. The resulting material is heated gently until the methoxyethyl mercury acetate is dissolved in the solution. The resulting liquid concentrate is a clear, stable solution, amber in color and soluble in water. It is dilutible in use to dilutions of 1:200 to 1:1000 (i.e., one part of concentrate to 1000 parts of water). It has been found to be particularly useful as a fungicide and a sapstain inhibitor; but this material may also be used on cellulosic fibers in paper making and for agronomic uses such as in the treatment of orchards or other growing plants of fungicidal purposes. The sapstain control of this composition on Southern Yellow Pine is particularly satisfactory.

Demonstration B.If a procedure is carried out that is the same as that of Demonstration A except that the nonionic emulsifier used is nonyl thiophenol ethoxylated with 4 moles of ethylene oxide, it is found that comparable results in homogeneity and water compatibility are obtained.

Demonstration.lf the procedures of Demonstrations A and B are repeated except that the methanol is replaced by tripropylene glycol monomethyl ether, it is found that the homogeneous concentrate is formed more readily. The sodium unsymmetrical trichlorophenate used in Demonstrations A, B and C has distinctly superior water-solubility as compared to more highly chlorinated polychlorophenates, and it has been found that it is not essential to homogeneity to employ the alkyl, ether, and homogeneity may be obtained merely by the use of the aqueousalcoholic system in the manner hereinbefore described (preferably in combination with the nonionic synthetic emulsifier).

Demonstration D.-Liquid X is first prepared by dissolving 40 parts of technical pentachlorophenol in parts of tripropylene glycol monomethyl ether, 13 parts of 50% aqueous sodium hydroxide, and 32 parts of water (the resulting liquid X has a pH between 11 and 12).

A charge of 90.7 parts of liquid X is heated with 1.6 parts of phenyl mercury lactate plus 7.7 parts of additional water until the material achieves homogeneity. The resulting concentrate has a pH of 10 and it is readily dilutable to 1:200 in water to obtain a particularly satisfactory composition for sapstain control and fungicidal purposes.

Demonstration E.Substantially the same results are obtained if, in carrying out the procedure of Demonstration D, the 15 parts of tripropylene glycol monomethyl ether used in the preparation of liquid X are cut in half and 7.5 parts of methyl carbitol or butyl Cellosolve is substituted therefor. The resulting concentrate is found to have homogeneity and to be soluble in water and readily dilutible therein.

Demonstration F .A procedure is carried out that is the same as that described in Demonstration D, except that the amount of liquid X used is 90.8 parts, the amount of water used is 6.8 parts and (in place of the phenyl mercury lactate) 2.4 parts of methoxyethyl mercury acetate is used, and it is found that the resulting homogeneous concentrate has a pH of 10 and is soluble in water and readily dilutible therein up to 1:200 to obtain a apstain control formulation.

Demonstration G.A charge of 474 parts of liquid X, 42 parts of water, 9.7 parts of sodium metaborate (NaBO AI-I O), and 0.8 parts of phenyl mercury lactate is heated until the organic mercury compound apparently goes into solution to obtain a clear concentrate which has a pH of about 10. This concentrate may be readily diluted to 1:100 in water to obtain a particularly satisfactory sapstain control formulation.

In addition, it has been noted that much greater ease of solution is obtained if the phenyl mercury lactate is sprayed from a concentration of inert volatile solvent such as methanol onto the sodium metaborate, before the sodium metaborate is introduced into the system comprising liquid X and the water. If, in contrast, borax decahydrate is used in place of the sodium metaborate tetrahydrate, it is found that, even though the phenyl mercury lactate is sprayed onto the borax powder, the rate of solution in the combination of liquid X and Water is much slower. This rate of solution can be accelerated by the addition of about 1 part of sodium hydroxide which will shift the pH from approximately a pH of 9 with the borax alone to a pH approaching 11 (and which will, of course, effect a conversion of borax to metaborate).

Demonstration H.A solution is first prepared from 41.8 parts of technical sodium pentachlorophenate in powdered form, 13.9 parts of tripropylene glycol monomethyl ether and 40 parts of water. To this is first added 1.5 parts of sodium hydroxide; and then 2.4 parts of methoxyethyl mercury acetate is added and the composition is heated to dissolve the organic mercury compound so as to obtain a clear concentrate having a pH of about 10 and having water-solubility. The concentrate is diluted 1:200 in water and is found to be useful in sapstain control.

Demonstration I.A solution is first prepared from 22.6 parts of powdered technical sodium pentachlorophenate, 59 parts of water and 7.4 parts of tripropylene glycol monomethyl ether. To this solution is then added 10.1 parts of sodium metaborate tetrahydrate on which have been deposited 0.9 part of phenyl mercury lactate in the manner described in the second paragraph of Demonstration G, and the resulting material is heated until the organic mercury compound apparently goes into solution to yield a clear concentrate having a pH of about 10. This material is soluble in water and when diluted 1:100 in water it yields a very satisfactory sapstain control composition.

Demonstration J.A solution is first formed from 48 parts of liquid X and 40.8 parts of water, to which is then added 9.8 parts of sodium metaborate tetrahydrate upon which has been deposited 1.4 parts of methoxyethyl mercury acetate. The mixture is heated until the organic mercury compound appears to go into solution and a clear concentrate is obtained having a pH of about 10. This material is diluted 1:100 in water and is found to have excellent sapstain control properties.

Demonstration K.A procedure is carried out that is the same as that described in the previous Demonstration J except that the organic mercury compound used in phenyl mercury salicylate, and it is found that substantially the same results are obtained. In addition, if the initial solution of liquid X and water has added thereto 2 parts of nonyl phenol ethoxylated with 9 to 10 moles of ethylene oxide, it is found that homogeneity is achieved more rapidly in the preparation of the concentrate.

Demonstration L.A solution is first prepared from 40.5 parts of technical powdered sodium pentachlorophenate, 13.8 parts of tripropylene glycol monomethyl ether, and 416 parts water. To this is added 1.5 parts of sodium hydroxide, followed by 1.6 parts of phenyl mercury lactate and the composition is heated until the organic mercury compound goes into solution to obtain a clear concentrate having a pH of about 10. This concentrate is diluted to 1:200 in water and is found to have excellent sapstain control properties.

If the procedure of the foregoing paragraph is repeated, except that one-half of the tripropylene glycol monomethyl ether is replaced by methyl carbitol, and 1 part of monyl phenol ethoxylated with 9 to moles of ethylene oxide is added to the initial composition of the pentachlorophenate, water and ether, it is found that the homogeneity is achieved more rapidly when the organic mercury compound is added.

Demonstration M .A charge of 22.8 parts of powdered technical sodium pentachlorophenate is dissolved in 58.3 parts of water, 7.4 parts of tripropylene glycol monomethyl ether and 10.1 parts of sodium metaborate tetrahydrate. To this is added 1.4 parts of methoxyethyl mercury acetate and the mixture is heated until it clears to obtain a homogeneous concentrate having a pH of about 10, which is readily dilutible 1:100 in water to obtain a sapstain control composition.

Demonstration N.-An initial solution is formed from 47.5 parts of liquid X, 19.5 parts of ethylene glycol and 12.8 parts of water. To this is added 1 9.5 parts of sodium metaborate tetrahydrate, and then 0.8 part of phenyl mercury lactate and the material is heated until it clears. The resulting homogeneous concentrate has a pH of about 11 and it is dilutible 1:100 in water to obtain a particularly suitable sapstain control composition.

In the foregoing formulation it will be noted that the ethylene glycol-water system uses a somewhat larger than normal quantity of sodium metaborate. The amount of sodium metaborate used in the practice of the instant invention, as in the case of other alkali metal borates, may be as much as 20%.

A particularly significant feature of the instant invention resides in the fact that the concentrates of the instant invention may be readily diluted 12100 to 121000 in water to obtain compositions that are particularly useful in the sapstain control art and compositions which are particularly useful as fungicides.

Upon a careful examination of the foregoing formulations, it will be noticed that a complex compound involving the organic mercury compounds, the borate ion and the hydroxylated compounds is formed. It is thought that a stable liquid sapstain is thus achieved. It is, of course, understood that other theories may be used to explain the novel and unexpected results attained by the instant invention.

It will be understood that modifications and variations may be effected without departing from the spirit and scope of the novel concepts of the present invention.

We claim as our invention:

1. A stable liquid sapstain concentrate eifective against a oroad spectrum of microorganisms that attack lumber and veneers which comprises; a soluble borax between about 8 to 10% by weight, water between about 36 to 47% by weight, 50% caustic soda between about 11 to 15% by weight, methyl alcohol between about 7.0 to 13.0% by weight, ethylene glycol between about 1.1 to 3.0% by weight, propylene glycol monomethyl ether between about 1.1 to 3.0% by weight, halogenated phenols between about 19 to 25% by weight and organic mercury salts between about 0.1 to 0.8% by weight.

2. A stable liquid sapstain concentrate effective against a broad spectrum of microorganisms that attack lumber and veneers which comprises; about 9.2% sodium tetraborate decahydrate, about 42.0% water, about 13.3% of a 50% sodium hydroxide solution, about 9.7% methanol, about 1.6% propylene glycol monomethyl ether, about 1.6% ethylene glycol, about 21.2% chlorinated phenols, and about 0.40% phenyl mercuric lactate.

3. A stable liquid sapstain concentrate effective against a broad spectrum of microorganisms that attack lumber and veneers comprising about 9.2% sodium tetraborate decahydrate, about 42.0% water, about 13.3% of a 50% sodium hydroxide solution, about 9.7% methanol, about 1.6% propylene glycol monomethyl ether, about 1.6% ethylene glycol, about 21.2% of a stable, free-flowing solid, melt-derived complex crystalline composition containing between 70 and 82.5% by weight of 2,3,4,6-tetrachlorophenol and correspondingly between 30 and 17.5%

by weight of pentachlorophenol, and about 0.40% phenyl mercuric lactate.

4. A stable liquid sapstain concentrate effective against a broad spectrum of microorganisms that attack lumber and veneers comprising about 9.2% sodium tetraborate decahydrate, about 42.0% water, about 13.3% of a 50% sodium hydroxide solution, about 9.7% methanol, about 1.6% propylene glycol monomethyl ether, about 1.6% ethylene glycol, about 21.2% of a stable, free-flowing solid, melt-derived complex crystalline composition containing about by weight of 2,3,4,6-tetrachlorophenol and about 20% by weight of pentachlorophenol, and about 0.40% phenyl mercuric lactate.

5. A stable liquid sapstain concentrate effective against a broad spectrum of microorganisms that attack lumber and veneers comprising; 8 to 10% by weight of a soluble borax, water between about 30 to 60% by weight, 8 to 15% by weight, of a 50 to potassium hydroxide solution, 7 to 13% by weight of methyl alcohol, 1.1 to 3% by weight of ethylene glycol, 1.1 to 3% by weight of dipropylene glycol methyl ether, 19 to 25 by weight of halogenated phenols, and 0.1 to 0.8% by weight of an organic mercury salt.

6. A stable liquid sapstain concentrate effective against a broad spectrum of microorganisms that attack lumber and veneers comprising; 8 to 10% by weight of a soluble borax, water between 30 to 60% by weight, 8 to 15 by weight of a 50 to 90% potassium hydroxide solution, 7 to 13% by weight of methyl alcohol, 1.1 to 3% by weight of ethylene glycol, 19 to 25 by weight of a mixture of about 80% 2,3,6drichloro-4-fiuoropheno1 and about 20% pentaohlorophenol and 0.1 to 0.8% by weight of an organic mercury salt.

7. A stable liquid sapstain concentrate effective against a broad spectrum of microorganisms that attack lumber and veneers comprising; 8.57% by weight of sodium tetraborate decahydrate, 55.1% by weight of water, 9.15% by weight of a 88.92% potassium hydroxide solution, 3.02% by weight of ethylene glycol, 3.02% by weight of dipropylene glycol methyl ether, 20.77% by weight of a stable, free-flowing solid, melt-derived complex crystalline composition containing about 80% by weight of 2,3,4,6-tetrachlorophenol and about 20% by weight of pentachlorophenol, and 0.37% by weight of phenyl mercuric lactate.

8. A method of controlling Ascocyte, Cerastostomella, Fungi imperfecti, green mold and white mold in lumber and veneer that consists of subjecting the lumber and veneer to contact with a ready-to-use solution of a stable liquid sapstain concentrate prepared by mixing in amounts based on the total weight of the resulting solution, a soluble borax in an amount between about 8 to 10% by Weight, water in an amount between 30 to 60% by weight, 50% alkali metal hydroxide in an amount between about 11 to 15% by weight, C -C saturated alcohol in an amount between 8.1 to 16% by Weight, propylene glycol monomethyl ether in an amount between about 1.1 to 3.0% by weight, halogenated phenols in an amout between about 19 to 25 by weight, and organic mercury salts between about 0.2 to 0. 8% by weight, and heating such resulting solution with continuing agitation until a stable liquid product is obtained.

References Cited by the Examiner UNITED STATES PATENTS 2,331,268 10/1943 Flenner et al. 167-38.7 2,423,262 8/1947 Sowa 167-30 2,867,563 1/1959 Musser et al. 167-30 2,925,361 2/1960 Bollenback 167-38.7

FOREIGN PATENTS 511,542 4/ 1955 Canada.

MORRIS O. WOLK, Primary Examiner.

F. W. BROWN, Assistant Examiner. 

8. A METHOD OF CONTROLLING ASCOCYTE, CERASTOSTOMELLA, FUNGI IMPERFECTI, GREEN MOLD AND WHITE MOLD IN LUMBER AND VENEER THAT CONSISTS OF SUBJECTING THE LUMBER AND VENEER TO CONTACT WITH A READY-TO-USE SOLUTION OF A STABLE LIQUID SAPSTAIN CONCENTRATE PREPARED BY MIXING IN AMOUNTS BASED ON THE TOTAL WEIGHT OF THE RESULTING SOLUTION, A SOLUBLE BORAX IN AN AMOUNT BETWEEN ABOUT 8 TO 10% BY WEIGHT, WATER IN AN AMOUNT BETWEEN 30 TO 60% BY WEIGHT, 50% ALKALI METAL HYDROXIDE IN AN AMOUNT BETWEEN ABOUT 11 TO 15% BY WEIGHT, C1-C2 SATURATED ALCOHOL IN AN AMOUNT BETWEEN 8.1 TO 16% BY WEIGHT, PROPYLENE GLYCOL MONOMETHYL ETHER IN AN AMOUNT BETWEEN ABOUT 1.1 TO 3.0% BY WEIGHT, HALOGENATED PHENOLS IN AN AMOUNT BETWEEN ABOUT 19 TO 25% BY WEIGHT, AND ORGANIC MERCURY SALTS BETWEEN ABOUT 0.2 TO 0.8% BY WEIGHT, AND HEATING SUCH RESULTING SOLUTION WITH CONTINUING AGITATION UNTIL A STABLE LIQUID PRODUCT IS OBTAINED. 